The present invention relates generally to arc detection, and more particularly, to a non-contact arc detection apparatus and method.
The presence of arcing poses significant safety issues to individuals working in and around power distribution components. Historically, arc detection has been performed by level detection schemes from current sensing arc detectors in contact with the power line conductor, level detection by current sensors coupled to a power line conductor, rate-of-change of current or voltage from current transformers connected to the power line conductor, the change in phase relationship of the current on the power line conductor compared to an externally generated signal, and the comparison of the phase plane plot change of the current and voltage on the power line conductor. Each of the above methods and apparatuses have required direct contact, coupled sensing, or direct connection to the monitored power line. Further, methods and prior art have been direct or coupled to only single power lines.
In the case of underground vaults, workers often encounter more than a single power line, resulting in the need to monitor each line. In addition to the need to know of potential electrical safety hazards prior to entering the vaults, workers need to be able to monitor potential arcing problems while working with distribution cables and components in these vaults to alert them when arcing conditions occur.
Limitations of the above prior art methods include problems associated with unknown vault conditions prior to vault egress and the condition of installed equipment in vaults where vault flooding may compromise electronic equipment and lack of early warning devices and methods during the time work is performed in the vault. Further limitations of the number of cables in the vault requiring monitoring are apparent.